Render chessboard when the contact accepts the user's request.
Add position information to the css class attributes
of the chessboard pieces and squares. (Eventually, try to migrate to
pure react.)
Log moves to assist development.
Abandon pure-render-mixin.
Add comment.
Add a keypath for the chess context.
Comment out assertions as they were the principal cause
of much latency.
Attain chess context from the server-initialized app-state.
Add chess context to the packet of data sent by
the server to clients.
Work on updating chessmen's positions on the board.
Add the fn #push.
Add comment.
Add the fns #b/not and #filter2.
Add a keypath for the board of a chess context.
Add the fn #reduce.
Rerender the board upon a valid move; trigger
the reversion of a jquery droppable to its orig position upon an invalid move.